Customized Applications for Mobile networks Enhanced Logic, or CAMEL (ETSI TS 123 078) for short, is a set of standards designed to work on either a GSM core network or UMTS network. They allow an operator to define services over and above standard GSM services/UMTS services. Many services can be created using CAMEL, and it is particularly effective in allowing these services to be offered when a subscriber is roaming, like, for instance, no-prefix dialing (the number the user dials is the same no matter the country where the call is placed) or seamless MMS message access from abroad. CAMEL Application Part (CAP) portable software provides mechanisms to support operator services beyond the standard GSM services for subscribers roaming within or outside their home network. The CAP product extends the Intelligent Network framework to GSM/3G networks for implementing services. CAMEL is used when the subscriber is roaming between networks, allowing the home network to monitor and control calls made by the subscriber. CAMEL provides services such as prepaid roaming services, fraud control, special numbers (e.g., 123 for voicemail that works everywhere) and closed user groups (e.g., office extension numbers that work everywhere).
The Diameter Credit Control Application is specified in RFC 4006. It can be used to provide real-time credit control for various applications, including, for example, messaging services, gaming services, video services, etc. The Application is used between the network element providing the service (client) and a credit control server. Redirection of sessions is used by Diameter Credit Control Applications (DCCA-RFC 4006) as a means to redirect a user to a different destination to engage with additional services. This includes, for example redirection of prepaid users to a service for adding additional credit to a prepaid account in a top-up process. Redirection is a key enabler for advanced charging features such as On-The-Fly top-up.
Re-Authorization Request (RAR) and Re-Authorization Response (RAA) are defined in RFC3588 and are used in DCCA/Ro RFC4006 by the OCS to force a credit reauthorization by the network for example after a top-up operation. However, in CAMEL there is no means to request the Mobile Switching Center (MSC) to generate an ApplyChargingReport. Accordingly, following a top-up, notice of additional credit may never reach the service provider—this results in termination of the user session despite the presence of sufficient credit for use of the service. This is disadvantageous to the user because the user is unable to easily continue with the activity the user was engaged in. This is also disadvantageous to the service provider, because the user may choose not to consume further services.
It would therefore be desirable to provide a system and method which overcome the limitations of CAMEL systems which do not natively support reauthorization functionality.